One example of the related multichannel acoustic signal processing system is described in Patent literature 1. This system is a system for extracting objective voices by removing out-of-object voices and background noise from mixed acoustic signals of voices and noise of a plurality of talkers observed by a plurality of microphones arbitrarily arranged. Further, the above system is a system capable of detecting the objective voices from the above-mentioned mixed acoustic signals.
FIG. 3 is a block diagram illustrating a configuration of the noise removal system disclosed in the Patent literature 1. A configuration and an operation of a point of detecting the objective voices from the mixed acoustic signals in the above noise removal system will be explained schematically. The system includes a signal separator 101 that receives and separates input time series signals of a plurality of channels, a noise estimator 102 that receives the separated signals to be outputted from the signal separator 101, and estimates the noise based upon an intensity ratio coming from an intensity ratio calculator 106, and a noise section detector 103 that receives the separated signals to be outputted from the signal separator 101, noise components estimated by the noise estimator 102, and an output of the intensity ratio calculator 106, and detects a noise section/a voice section.